Sure here is : 

[Group]

GroupCount=4

GroupLeft=466

GroupTop=193

GroupRight=3028

GroupBottom=1181

GroupMax=0

Locked=0

[GroupyEntry1]

StoreApp=1

OwnerProcess=microsoft.windowscommunicationsapps_8wekyb3d8bbwe!microsoft.windowslive.mail

NewTabName=

RunElevated=1

NoPatternMatching=1

Target=microsoft.windowscommunicationsapps_8wekyb3d8bbwe!microsoft.windowslive.mail

MatchingClass=ApplicationFrameWindow

[GroupyEntry2]

StoreApp=1

OwnerProcess=Microsoft.YourPhone_8wekyb3d8bbwe!App

NewTabName=

RunElevated=1

NoPatternMatching=1

Target=Microsoft.YourPhone_8wekyb3d8bbwe!App

MatchingClass=WinUIDesktopWin32WindowClass

[GroupyEntry3]

OwnerProcess=C:\Users\Nat\AppData\Local\Programs\Rambox\Rambox.exe

NewTabName=Messenger

RunElevated=1

NoPatternMatching=0

CommandLine=

WorkingDirectory=C:\Users\Nat\AppData\Local\Programs\Rambox

Target=C:\Users\Nat\AppData\Local\Programs\Rambox\Rambox.exe

MatchingClass=Chrome_WidgetWin_1

[GroupyEntry4]

OwnerProcess=C:\Users\Nat\AppData\Local\Programs\signal-desktop\Signal.exe

NewTabName=

RunElevated=1

NoPatternMatching=0

CommandLine=

WorkingDirectory=C:\Users\Nat\AppData\Local\Programs\signal-desktop

Target=C:\Users\Nat\AppData\Local\Programs\signal-desktop\Signal.exe

MatchingClass=Chrome_WidgetWin_1

Thanks for your quick answer!

Are you running with UAC disabled on your computer?

So for now I disabled UAC, because I prefered not to have to manually click "Yes" to every prompt. 

I also prevented Signal and Discord from opening on startup, and something changed. 

Now, when clicking the Groupy shortcut, Discord does group automatically, but Signal still don't. And it doesn't even open in a window anymore, it straight up goes to the notification area. Even though I have it disabled in Signal Settings.

(for proof : when I first launch Signal without the Groupy shorcut, it opens normally, in a normal window)

And the odd thing is : when I click on Signal in the notification area to maximize it, it does automatically add itself to the group. 

I'd still like for it not to behave like that and to automatically group with the rest of the apps when I click on the Groupy shortcut.